Three years after the Japan tsunami, researchers here have released a new animated video that not only shows what happened that day but provides clues on how the state can better prepare for future disasters.

The Pacific Tsunami Warning Center's video shows how waves generated by the 9.0 magnitude earthquake in Japan crossed the Pacific Ocean through Hawaii before bouncing back from West Coast to hit the islands again.

"That's us here," said Gerard Fryer, senior geophysicist at the Pacific Tsunami Warning Center, pointing to dots on screen showing a simulation of the 2011 tsunami's path.

"The main energy went to our south. If it had been pointed right at us, (the waves) would have been higher. It would have been 50 percent higher."

Fryer said that much of wave energy remained around the islands after the main thrust of the tsunami had passed, creating waves as high as 17 feet on the North Shore while sending dangerous surges that closed well-known attractions like Hanauma Bay.

Fryer said the state's alert system worked well that day, with one exception.

"We canceled (the warning) too early. The tsunami came in at three in the morning and we canceled everything at 11:30," he said.

"Two hours after that someone got swept out to sea in Waikiki and the lifeguards had to go out and get him. And while they were helping him, 11 other people got swept out."

The simulation program allows warning center researchers to forecast the potential impacts of a tsunami on Hawaii, no matter where its generated.

That program can provide a simulated forecast in as little as 20 minutes, giving emergency officials hours to plan ahead.